In her search for more advertising revenue, Yahoo chief Marissa Mayer has decided to team up with her former employer, Google.

In a post on its website Wednesday, Yahoo said it will begin using Google's AdSense and AdMob services as it seeks to boost sales from the content on its own pages.

The Sunnyvale Web portal company signed a global, nonexclusive agreement with Google for contextual advertisements. The ads will appear on Yahoo's sites for finance, news, sports and autos, said Sara Gorman, a spokeswoman for the company.

Chief Executive Officer Mayer plans to get users spending more time on a dozen of Yahoo's top sites, she said in a call with analysts last month. The partnership with Google, her former employer, could help Yahoo boost revenue from those pages, said Mark Mahaney, managing director at RBC Capital Markets in San Francisco.

He said the move indicates that Yahoo believes it will generate revenue, and that it should be "a near-term positive."

Yahoo stock rose 1.5 percent to $20.15 in extended trading after the announcement of the new partnership.

Google already distributes similar ads to thousands of websites, a service that has helped establish it as the Internet's most prosperous company. Yahoo has been struggling to attract more advertisers, even though marketing budgets have been shifting to the Internet.

Google retains part of the revenue generated from the ads shown on its partners' sites. The revenue split with Yahoo wasn't disclosed.

Google is expected to retain its lead in the $17.7 billion U.S. market for display ads this year, with an 18 percent share, while Facebook will have 15 percent and Yahoo will slip to 8 percent, eMarketer estimates.

Users of Yahoo's sites won't see any noticeable difference in ads, the company said.

"By adding Google to our list of world-class contextual ads partners, we'll be able to expand our network, which means we can serve users with ads that are even more meaningful," Yahoo's posting said.

During an interview last month at the World Economic Forum in Davos, Switzerland, Mayer said she prefers to work with large companies like Google, Apple and Facebook rather than build expensive new products such as smartphones and social networks.

"We are able to work with some of these players, who have a lot of strength, in order to really bolster our user experiences that we offer on the Yahoo site," Mayer said.